I was standing at the locker in the gym today, and I suddenly thought it would be funny if all combinations on my 4-digit lock actually worked.

As long as the person who wants to steal my stuff believes that there’s only one working code — and I believe that too — the system stays safe.

I think this happens a lot. On a fundamental level, either all combinations work, or many different keys do, but because both parties believe that only one combination is correct, the whole thing remains secure.

You can approach quantum mechanics the same way. If you act as if it’s a simple puzzle you can solve in a few seconds, then it becomes a simple puzzle you can solve in a few seconds. I think many people don’t even dare to start because they believe they first have to study it deeply.

How to crack the hardest puzzles

• always use ingredients from different traditions: religion, science, spirituality

• I always pick one set of thoughts that is true, and one set that is not true

• choose things from different disciplines. Also bring in thoughts and feelings that have very little to do with the problem itself.